Piano-player



C. H. SPENCER.

PIANO PLAYER.

APPLICATION FILED APR. 19, 1919.

1,324,700, Patented Dec. 9,1919.

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APPucA .19. 1918. 1,324,700. Patented Dec. 9,1919.

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UNITED s ra'trns PATENT OFFICE.

CHARLES H. SPENCER, 0F BALTIMORE, MARYLAND, ASSIGNOR TO HENRY S.DULANEY,

r OF BALTIMORE, MARYLANDv lPIANC-PLAYEB.

Application filed April 19, 1918.

To all whom it may-concern.-

Be it known that 1, CHARLES H. SPENCER, a citizen of the United Statesof America, residing in the city of Baltimore, State of Maryland, haveinvented certain new and useful Improvements in Piano-Players, of whichthe following is a specification.

Apparatus of this type, while it has attained a wide sale and a highdegree of pop ularity, :is found objectionable by many people ofsensitive musical perception on account of the so-oalled automatic ormechanical effect. This is largely due to the fact that while themechanical eifort necessary to playing the different notes is widelyvarying from bass to treble, the force supplied by the playing apparatusis the same throughout so that the higher notes are most sharplyactuated or struck. This gives a harsh, hard, metallic tone, resultingin the well-known effect, generally termed mechanical. To avoid thisobjectionable effect, I have by means of my improved apparatus provideda playing impulse which is graduated or varied in accordance with theresistance offered at the different notes, that is, the pressure appliedby the playing means or pneumatic at the bass notes is the maximumproduced by the apparatus, and the playing efiort or pressure is reducedon a ratio corresponding to the reduction in resistance for eachsucceeding higher note up to the treble end of the key-board.

In the form of the invention shown, the pneumatic. player apparatus ispreferably connected directly to the piano action, each pneumatic unitcontacting with the piano action at some convenient point and moving theaction operatively each time the particular pneumatic unit is actuated.The actual force or energy generated by each pneumatic member may bevaried in any suitable and convenient manner, as by varying the lengthof the lever arm by which the pneumatic pressure from each unit issupplied to the piano action, or by varying the size of the bellows orstriker embodied in each unit, or more particularly the area of theinternal surface of the moving member of the bellows or striker exposedto the air pres sure or vacuum of the wind chest. In the preferred formof the apparatus, as illustrated herein, this result is obtained bycombining these two elements, that is, increasing both the leveragewhich the air pressure Specification of Letters Patent.

Patented Dec. 9, 1919.

Serial No. 229,517.

is applied to the piano action and increasing the size of the bellows bymeans of which the vacuum or air pressure, the vacuum being merelycounted as negative pressure, is applied to the piano action, the sizeof the bellows and the length of the leverage cor responding o andvarying directly with the pressure which must be applied to the pianoaction for each note in order to play that note. I

In the accompanying drawing, I have illustrated a pneumatic unit, thepreferred manner of connecting the same to the piano action, and a fullset of pneumatics installed in a piano according to the preferredembodiment of my invention.

Figure 1 is a vertical, central, longitudinal section through a singlepneumatic unit;

Fig. 2 is a fragmentary vertical section through a piano showing asingle unit of the piano action in elevation, and illustrating themanner of applying a pneumatic unit thereto; and

Fig. 3 is a plan view of a piano withportions of the casing broken away,showing a series of pneumatics in place, the playing effort beinggraduated to correspond to the resistance offered at the respectivenotes.

Referring to the drawings by numerals, each of which is used to indicatethe same or similar parts in the diflerent figures, the pneumatic unit,illustrated in section in Fig. 1, includes a diaphragm casing and valvecasing 1 secured to the transversely extending wind box 2 which issupported at its ends on the piano frame and otherwise suitably braced,carrying all the pneumatic units, and a bellows or striker consisting ofa fixed plate a and a swinging plate or lever arm 5, and anaccordion-plaited fabric connection 13. The diaphragm and Valve casing 1is formed of two portions or sections, 6 and 7 split on a horizontalplane at 8 to provide convenient access to and support for the diaphragm9. This diaphragm is substantially horizontal and intermediately placedin the diaphragm chamber 10 which is formed partly in the top section 6and partly in the bottom section 7 of the casing 1, the edges of thediaphragm being between the adjacent surfaces of the two sections andsecured to the surface of one sec-- may occupy each but a single keyspace and at the same time have the diaphragms 9 of the requisite arearequired to actuate the valves as hereinafter described, the latter aremade long and narrow, the requisite area being at least five or sixtimes the area of the valve. To permit the diaphragm to return to normalposition after opening the valve, it has a very small bleeder orequalizing opening 11, preferably formed in a piece of mica or otherhard material 12 set in the diaphragm near the center. The wind orpneumatic chamber 2, as already pointed out, extends the full length ofthe piano supporting all the pneumatics and is in turn itself supportedon the frame of the piano at the sides. The inside of this wind box 2from which the air is exhausted by suitable apparatus well-known to theart, is connected to the diaphragm chamber of each of the pneumatics bya nipple or passage 14 which leads from the top of the diaphragmchamber, and this same top section 15 of the diaphragm chamber is inturnconnected to the Valve chamber 16 by an opening 17 con trolled by avalve 18. This valve 18 rests on an upwardly disposed seat 19 and islifted from this seat in the operation of the pneumatic by means of aflat plate lever 20 which rests on the diaphragm 9 and is actuatedthereby. This plate 20, as shown, has an opening 21 over the bleederopening to prevent blocking of the latter during operation, allowing afree air passage in bleeding. The opening 17 is directly beneath asecond valve opening 22 leading upward to the outside a1r and having adownwardly disposed seat 23 with which a valve 24 cooperates, the samehaving a screw stem 25 projecting through the valve preferably havingits upper end flattened to be engaged by a key and its lower enddepending so that it is normally in contact with the valve 18, the uppervalve being opened by gravity and outside air pressure when the lowervalve is closed and closed by the action of the lower valve against thestem 25 when the latter valve is opened.

Leading to the valve chamber 16 from the striker or bellows 3 is anopening 26 and each pneumatic has a. nipple 27 for the connection of asuitable tube 28 leading to the tracker bar, the said nipple beingconnected to the bottom section of the diaphragm chamber by a tube 29.

In the operation of the pneumatic unit or individual pneumatic, the airis exhausted from the wind chest or passage 2 by a suitable pumpactuated by the pedals or other means, and the perforated sheet of musicis passed over the tracker bar. The tubes 28 are connected each to acorresponding opening in the tracker bar. W hen a slot or openmg in thesheet of music comes into registration with the corresponding opening inentrance of air to the bottom side of the dia-.

phragm or lower half of the diaphragm chamber. As air is at the sametime exhausted from the passa e 2, much faster than it can pass throughthe bleeder o ening 12 in the diaphragm, the latter is sue ed up againstthe upper side of the upper wall of the chamber, lifting the lever 20and opening the valve 18.- The lifting of this valve at the same timecloses the valve 24 so that the existing vacuum or negative pressure inthe passage 2, maintained by a suitable pump, exhausts the air from orsets up a vacuum in the striker 3, the air being drawn through thepassage 26, the valve chamber 16, the passage 17 which is controlled bythe valve 18, theupper half of the diaphragm chamber 10, and the nipple14. This causes the immediate collapse of the striker in response to theexternal air pressure, lifting or swinging the bottom plate 5 and thelever 30 to their uppermost position in which the bottom plate 5 restsagainst the stop screw 70. In the form of the invention shown, the lever30 is connected to the piano action and actuates the correspondin noteas it rises. As soon as the opening in the music roll passes out ofregistration with the corresponding opening in the tracker bar, theentrance to the tube 28 is closed, the supply of air to the under sideof the diaphragm is cut off and the bleeder opening 15 in the diaphragmpermits the pressure on the two sides to immediately become equalizedwhen the valve lever 20 is dropped. The valve 18 also drops uponits seatto which it is guided by the depending prongs 31, and the valve 24 opensin response to gravity and outside air pressure, admitting the outsideair which fills the striker bellows permitting the lever 30 and theplate 5 to drop to the bottom position shown in Fig. 1.

In Fig. 2 I have illustrated roughly a piano action for a single unit ornote. According to the usual practice, each unit of the piano action isactuated by a depending abstract 36 guided by a guide lever 37 pivotedto a depending bracket 38 and to a low point on the connecting rod at39. In the manual operation of the piano, this rod is raised, actuatinga striker not shown by means of the usual pivoted key 40 which engagesthe rod 36 from beneath each time the corresponding note is played andimparts to it an upward thrust when the forward end 41 of the key isdepressed.

As a means for operating the piano automatically, a series of playerpneumatics, as already described. is in the preferred form of theinvention placed on a single supporting bar extending across the pianoin the vicinity of the action, the supporting bar in t e p es t instancebeing the wind box or lgo 1 matic units'has an actuating or lever arm 30attached to the bottom plate 5. This, in the assembled form of theapparatus, is placed beneath the swinging end of the extension 44, asuitable felt pad being interposed, so

: that when the bellows is collapsed and the bottom plate 5 drawn up,the lever 30 contacting with the extension A of the guide lever 37raises the rod 36 and plays the note corresponding to the particularpenumatic and rod 36 actuated, it being understood that there is one rod36 and one action, such as illustrated in Fig. 2, to each note of thepiano and one pneumatic unit corresponding to each note and each rod 36.

Referring now to Fig. 3, we have the keys and pneumatics correspondingto the lower or bass notes on the left, and the keys and pneumaticscorresponding to the treble on the right. As has already been pointedout, the resistance offered by the piano action in playing the bassnotes is greater than that offered by the piano action in playing thetreble notes. In other words, the nearer the treble, the more sensitive,quicker, lighter and weaker the touch and in order to produce a naturalplaying effect, the impulse or efi'ort supplied in playing the notesshould correspond. In this way, the so-called mechanical efl'ectincident to all automatic players is redu ed or avoided. This may beaccomplished by a variety of methods; a shortening of the strikerchamber of the pneumatic gives exactly the desired effect.

In the present instance, I vary the length of the bellows, or moreproperly the length or area of the internal surface of the moving memberof the bellows or striker, using a short bellows for the treble and along bellows for the bass. The actual thrust and force applied with agiven air pressure, either positive or negative, varies directly withthe length of the bellows or exposed surface of the moving member,provided it is of a given width, as in the present instance. I thus havethe greater effort or thrust applied to the bass notes and a reducedeffort or thrust applied to the treble, it being understood that I usethe word exposed to mean exposed to the internal pressure of thepneumatic or bellows. Further, in the present instance, I have theupward thrust developed at the bellows applied to the rod 36 by means ofa lever arm composed of the plate 5 and actuator 30. The length of theactuator 30 being constant and the length of the plate 5, which is thebottom of the pneumatic, being varied and reduced toward the treble,eflects a corresponding change of ratio of the moment arm or lever armof the point of application of the force to the moment arm of the pointof delivery of the work, 2'. 0., the moment arm at the center of thebottom of the bellows about the pivot 46 and the moment arm at the endof the extension 30 about the same pivot. With the length of thebellows, the ratio of the moment arm of the force applied to the momentarm of the resistance or work done increases giving from this cause aproportionately increased pressure or effort to overcome the playingresistance.

In the form of the invention shown, I thus have the force developed bythe bellows, as well as the leverage of its application, reduced fromthe bass toward the treble, illustrating the application of the twoprinciples, that is, change of leverage and change of force applied tocorrespond to the playing resistance, in a single embodiment of theinvention.

The operation, functions served and the resulting advantages of thedevice have been fully discussed in connection with the description.

I have thus described my invention specifically and in detail in orderthat its nature and operation may be fully understood; however, thespecific terms herein are used descriptively rather than in theirlimiting sense and the scope of the invention is defined in the claims.

I claim 1. In a piano-player, a series of units, each beingapproximately of key width so as to occupy a single key space, onecorrespond ing to each note of the piano to be operated by the player,the units being arranged side by side in a single row, the positions ofthe units relative to the piano action of the cor responding notes beinguniform, each unit including a strikerbellows, the length of the bellowsbeing varied for the different notes, the longer bellows correspondingto the lower notes.

2. In a piano-player, a series of automatic player units of key width,one for each note of the piano to be operated by the player, the unitsbeing set side by side in a single row, each unit including a bellows ofgraduated length, the longer bellows operating the lower notes, thelength decreasing as the tone rises and the resistance decreases,supporting means to which each unit is secured, the series of playerunits thus mount ed forming a tapering member approximately the lengthof the keyboard, substan- -tially as shown and described.

3. In a piano-player, a series of automatic player units equal in nunber to the number of notes of the piano to be operated by the playerand set in a horizontal line extending across the piano parallel to theline of keys, each unit including a bellows of graduated length having amoving member actuated by the air pressure within the bellows, thebellows being of key width and the moving members of graduated length,means connecting the moving members to the piano action corresponding tothe respective notes, the moving members having the longer exposed areaoperating the lower notes, the length decreasing as the tone rises andthe resistance decreases.

4. In a piano-player, a series of player units of key width equal innumber to the number of notes of the piano to be operated by the playerand arranged in a single line across the piano, each unit correspondingto a note and each including a bellows, the bellows having a movingmember which swings with a lever-like action in correspondence with theinflation and deflation of the bellows, a swinging lever correspondingto each unit of the player, the swinging end of the lever being incooperative relatlon with the outer or swinging end of said movin memberof the bellows so that it is actuate by the bellows, the swinging leverbeing in cooperative relation with the piano action of the correspondingnote to actuate the same, the lengths of said levers in the respectiveunits bein graduated so that the leverage with whic the pneumaticpressure is applied to the piano action is decreased from the basstoward the treble end of the action.

Signed by me at Baltimore, Maryland, this 16 day of April, 1918.

CHARLES H. SPENCER. W'itnesses:

ZELLA KUHN, ALICE G. DONEGAN.

